Prostate diseases represent a significant health problem in the United States. After cardiac diseases and lung cancer, metastatic prostate cancer is the third leading cause of death among the American men over fifty years, resulting in approximately 31,000 deaths annually. The definitive diagnostic method of prostate cancer is core needle biopsy. Annually in the U.S., approximately 1 million prostate biopsies are performed. The average number of new prostate cancer patients detected by needle biopsy has stabilized around 200,000 per year. Due to the evolution in screening techniques, more cases are diagnosed at an earlier stage, when patients are candidates for some form of minimally invasive localized therapy typically delivered with needles. The majority of the cancer-free biopsied patients are likely to have benign prostate hyperplasia (BPH). Currently more than 10 million American men suffer from BPH. Significant attention has been focused on minimally invasive local therapies of this condition, because its definitive treatment, transurethral resection (TURP) is a highly invasive surgical procedure with potentially adverse side effects. Needle-based ablative therapies have shown promising results lately in the treatment of BPH.
Currently, transrectal ultrasound (TRUS) guided needle biopsy is primary technique being utilized for the diagnosis of prostate cancer [Presti J C Jr. Prostate cancer: assessment of risk using digital rectal examination, tumor grade, prostate-specific antigen, and systematic biopsy. Radiol Clin North Am. 2000 January; 38(1):49-58. Review] and contemporary intraprostatic delivery of therapeutics is also primarily performed under TRUS guidance. This technique has been overwhelmingly popular due to its excellent specificity, real-time nature, low cost, and apparent simplicity. At the same time, however, TRUS-guided biopsy fails to correctly detect the presence of prostate cancer in approximately 20% of cases [Norberg M, Egevad L, Holmberg L, Sparen P, Norlen B J, Busch C. The conventional sextant protocol for ultrasound-guided core biopsies of the prostate underestimates the presence of cancer. Urology. 1997 October; 50(4):562-6; Wefer A E, Hricak H, Vigneron D B, Coaldey F V, Lu Y, Wefer J, Mueller-Lisse U, Carroll P R, Kurhanewicz J. Sextant localization of prostate cancer: comparison of sextant biopsy, magnetic resonance imaging and magnetic resonance spectroscopic imaging with step section histology. J Urol. 2000 August; 164(2):400-4].
For the same reason, targeted local therapy today also is not possible with the use of TRUS guidance. Instead, major anatomical regions (or most often the entire prostate gland) are treated uniformly while trying to maintain the fragile balance between minimizing toxic side effects in surrounding normal tissues and providing/giving a sufficient therapeutic dose to the actual cancer. Also importantly, the transrectal ultrasound probe applies variable normal force on the prostate through the rectal wall, causing dynamically changing deformation and dislocation of the prostate and surrounding tissue during imaging and needle insertion, an issue that has to be eliminated in order to achieve accurate and predictable needle placement. The key to successful prostate biopsy and local therapy is accurate, consistent and predictable needle placement into the prostate, and some form of image guidance.
MRI imaging has a high sensitivity for detecting prostate tumors. Unfortunately, MR imaging alone, without concurrent biopsy, suffers from low diagnostic specificity. In addition, there are other fundamental obstacles that must be addressed when using MRI imaging techniques in prostate biopsy and related localized therapy of the prostate. Conventional high-field MRI scanners use whole-body magnets that surround the patient completely and do not allow access to the patients during imaging. Thus, the workspace inside the bore of the whole-body magnet is so extremely limited, that conventional medical robots and mechanical linkages do not fit inside the whole-body magnet. Also, the strength of the magnetic field being generated within the whole-body magnet is about 200,000 times stronger band the magnetic field of the earth. Due to these ultra-strong magnetic fields, ferromagnetic materials and electronic devices are not allowed to be in the magnet due to safety and/or imaging concerns, which excludes the use of traditional electromechanical robots and mechanical linkages.
Tempany, D'Amico, et al. [Cormack R A, D'Amico A V, Hata N. Silverman S. Weinstein M, Tempany C M. Feasibility of transperineal prostate biopsy under interventional magnetic resonance guidance. Urology. 2000 Oct. 1; 56(4):663-4; D'Amico A V, Tempany C M, Cormack R, Hata N, Jinzaki M, Tuncali K, Weinstein M, Richie J P. Transperineal magnetic resonance image guided prostate biopsy. J Urol. 2000 August; 164(2):385-7] proposed to use an open MRI configuration in order to overcome spatial limitations of the scanner. The magnet configuration for this open MRI configuration allows the physician to step inside the magnet and deliver biopsy and therapeutic needles into the prostate. This approach showed that it was possible to use an MRI imaging process to detect cancer previously missed by ultrasound guided needle biopsy and to perform targeted brachytherapy of the prostate. This technique has limitations, however, because it involves the use of an open MRI scanner. Perhaps most importantly, the incurred cost and complexity of open MRI imaging are substantial, especially when compared to transrectal ultrasound imaging.
Open magnets also tend to have weaker magnetic fields than the magnetic fields that are generated using closed magnets, thus open magnets tend to have lower signal-to-noise ratio (SNR) than the SNR for a closed high-field MRI scanners. Consequently, intra-operative images for an open magnet tend to be of a lower quality than the diagnostic images from a closed MRI scanner. While this approach seems to be acceptable when used in a research type of environment, it adds to the complexity and cost of the open MRI. Tempany et al. apply transperineal needle placement for both biopsy and brachytherapy, which is conventionally accepted for therapy, but for biopsy, it is a significantly more invasive route than through the rectum.
Traditionally, needles are placed into the prostate manually while observing some intra-operative guiding images, typically real-time transrectal ultrasound. TRUS biopsy is executed with entirely free hand. Transperineal needle placement is significantly more controlled by stepping transrectal ultrasound and template jigs, however, it still depends on the physician's hand-eye coordination. Therefore, the out comes of TRUS guided procedures show significant variability among practitioners.
Recently, a 6-DOF robot has been presented for transperineal needle placement into the prostate, but that kinematic concept is not applicable in transrectal procedures [G. Fichtinger, T. L DeWeese, A. Patriciu, A. Tanacs, D. Mazilu, J. H. Anderson, K. Masamune, R H. Taylor, D. Stoianovici: Robotically Assisted Prostate Biopsy And Therapy With Intra-Operative CT Guidance: Journal of Academic Radiology, Vol 9, No 1, pp. 60-74]. An industrial robot also has been applied to assist TRUS-guided prostate biopsy with the use of a conventional end-shooting probe [Rovetta A, Sala R: Execution of robot-assisted biopsies within the clinical context, Journal of Image Guided Surgery. 1995; 1(5):280-287]. In this application, the robot mimicked the manual handling of TRUS biopsy device in the patient's rectum, in a telesurgery scenario.
A robotic manipulator has been reported for use inside an open MRI configuration, which device is intended to augment the Tempany et al. developed system [Chinzei K, Hata N, Jolesz F A, Kikinis R, M R Compatible Surgical Robot: System Integration and Preliminary feasibility study, Medical Image Computing and Computer-assisted Intervention 2000, Pittsburgh, Pa. Lecture Notes in Computer Science, MICCAI 2000, Springer-Verlag, Vol. 1935, pp. 921-930]. The motors of this robot are situated outside the first magnetic zone, while the motors actuate two long arms to manipulate the surgical instrument in the field of imaging. This solution is not suitable for a closed magnet configuration. In addition, the long arms of this robotic manipulator amplify the effects of flexure and sagging, which can render this system inaccurate for certain procedures. Moreover, because the device is intended to be mounted permanently with respect to the MRI scanner, the robotic manipulator is not flexibly adaptable to different sides of the body.
Recently, a robot has been developed for use inside a conventional MRI scanner that is custom-designed for breast biopsy, [Kaiser W A, Fischer H, Vagner J, Selig M. Robotic system for biopsy and therapy of breast lesions in a high-field whole-body magnetic resonance tomography unit. Invest Radiol. 2000 August; 35(8):513-9]. This robot is mounted on the table of the scanner and it realized six degrees of freedom (6 DOF). This robot is demonstrated in accessing the breast, but it is not readily adaptable for abdominal and intracavity use. There also has been published variations of an in-MRI robot for stereotactic brain surgery, but the actual embodiments of that system also are not applicable in transrectal biopsy [Masamune et. al., Development of an MRI-compatible needle insertion manipulator for stereotactic neurosurgery. Journal of Image Guided Surgery, 1995, 1 (4), pp. 242-248].
Also, multiple investigators have studied tracking of surgical robots and interventional devices in intra-operative medical images. In most imaging environments, passive fiducials are attached to the interventional device in a priori known geometric arrangement, then traces of the fiducials are found in the resulting images [Yao J, Taylor R H, Goldberg R P, Kumar R, Bzostek A, Van Vorhis R, Kazanzides P, Gueziec A. A C-arm fluoroscopy-guided progressive cut refinement strategy using a surgical robot. Comput Aided Surg. 2000; 5(6):373-90; Susil, R. C., Anderson, J. H., Taylor, R. H., (1999) A Single Image Registration Method for CT-Guided Interventions. Lecture Notes in Computer Science, MICCAI99, Springer-Verlag, Vol. 1679, pp. 798-808]. In addition to passive tracking, MRI imaging offers the opportunity to apply micro-coil antennas as active fiducials [Derbyshire J A, Wright G A, Henkelman R M, Hinks R S. Dynamic scan-plane tracking using MR position monitoring. J Magn Reson Imaging. 1998, July-August; 8(4):924-32]. In this application, the signal processing software “listens” to a prominently present “signature” from the fiducial coils, allowing for accurate real-time calculation of the coil positions.
It thus would be desirable to provide a new device, apparatus, systems and methods for image-guided biopsy and/or a wide range of therapeutic techniques including needle therapy that employs high resolution MRI imaging inside a closed MRI scanner. It also would be particularly desirable to provide such devices, apparatuses, systems and methods for image guided biopsy and/or therapeutic techniques of the prostate, rectum, vagina or cervix, as well as an artificial opening created in the body such as for example those used in connection with laparoscopic procedures/techniques. It would be particularly desirable to provide such a device, apparatus, system and method that would replace the conventional manual technique with a remotely controlled needle insertion and guiding technique to maximize needle placement accuracy and also to minimize dynamic tissue deformation during the procedure. It also would be particularly desirable to provide such devices, apparatuses, systems and methods that employ real-time MRI guidance, are compatible with conventional high-field MRI scanners with no artifact, that can fit inside a closed whole-body magnet and not assume workspace for motion, that can perform needle insertion (e.g., transrectal needle insertion), that minimizes organ motion and deformation in a non-invasive manner and which provides three degree-of-freedom motion to reach a target within the body and selected by the user/medical personnel.